Fasteners & Lubrication

[Skyebot]

Hi Everyone,

I'm in the process of timing belt, water pump, and front of engine maintenance and beyond being mildly terrified of messing it up, I have questions regarding re-assembly - specifically lubricants and fasteners. Prior bicycle industry experience dictated grease every thread (aside for a few that received anti-seize/threadlock)

But with the heat and forces at play I'm unsure about what to do with timing belt tensioner plates and axles, water pump bolts, coolant junctions...even timing cover bolts.

I want to prevent corrosion and reach correct torque spec but... not sure if its grease, threadlock, or just clean threads.....

Any insight is appreciated!

Skye

[bobplyler]

I always use loctite (blue NOT red).

[18Fiatsandcounting]

I'm in the process of timing belt, water pump, and front of engine maintenance and beyond being mildly terrified of messing it up...

Skye, no need for excessive panic. In my 40+ years of wrenching away on these Fiats, I don't recall a single fastener that ever came loose when tightened properly. As bobplyler pointed out above, blue Loctite can be used for critical fasteners, but I don't consider timing belt cover fasteners to be critical.

I clean the threads with a solvent (usually acetone) and also the nut or threads on the block that it goes into (with a Q-tip). If threads are really dirty, I run over them with a brass wire brush.

The only fasteners that I put sealant on are the four bolts for the water pump, but only for the later engines. Early engines like the 1438 and 1608 had blind bolt holes for those bolts, so they weren't exposed to coolant on the backside. But I believe the 1756 engine has at least two or three water pump bolts that go into the coolant galley behind them. The 2L engine does. For those, I use thread sealer, and I use copper washers instead of the usual steel washers (copper washers provide additional sealing should any coolant go through those bolt holes in the pump).

Don't overtorque the M6 bolts for the water pump or for the coolant neck on the top of the head. Some manuals have the torque spec way too high, and that amount of torque will snap the bolt. Much sadness then ensues.... I usually torque to 7 or 8 ft lbs max.

-Bryan

[Skyebot]

Thanks Bob & 18Fiats,

Appreciate the notes!

As you're recommended, I worked to get everything as clean as possible (threads/block/etc.) using a bit of carb cleaner/brushes and used a light touch of blue loctite to tensioner pivot, tensioner spring stud and light anti-seize to tensioner pulley stud and water pump bolts (torqued to 7+/- ft lb thanks!) as the former will see coolant and latter does not have a head to easily remove (tho a jam-nut could do)

-Anti-seize was recommended by a former aircraft machinist and vintage car mechanic.
-ASide note, and to be determined - he recommended coating the water pump seal with a light coat of Lucas oil red and tacky grease to promote a seal that is hydrophobic + will fill in any voids... we will see.

Belt is back on and cooling system to be reinstalled shortly - I will get 'er started soon for a leak test....

Skye